4 files changed, 33 insertions(+), 18 deletions(-)

M pc/mmu.c
M pc/trap.c
M port/chan.c
M port/pgrp.c

@@ 106,6 106,10 @@ taskswitch(ulong pagetbl, ulong stack)
 {
 	tss.ss0 = KDSEL;
 	tss.sp0 = stack;
+tss.ss1 = KDSEL;
+tss.sp1 = stack;
+tss.ss2 = KDSEL;
+tss.sp2 = stack;
 	tss.cr3 = pagetbl;
 	putcr3(pagetbl);
 }

@@ 136,9 136,9 @@ trapinit(void)
 	sethvec(11, intr11, SEGIG, 0);
 	sethvec(12, intr12, SEGIG, 0);
 	sethvec(13, intr13, SEGIG, 0);
-	sethvec(14, intr14, SEGIG, 0);	/* page fault, interrupts off */
+	sethvec(14, intr14, SEGIG, 0);	/* page fault */
 	sethvec(15, intr15, SEGIG, 0);
-	sethvec(16, intr16, SEGIG, 0);	/* math coprocessor, interrupts off */
+	sethvec(16, intr16, SEGIG, 0);	/* math coprocessor */
 
 	/*
 	 *  device interrupts


@@ 223,7 223,9 @@ Proc *lastup;
 
 
 /*
- *  All traps
+ *  All trapscome here.  It is slower to have all traps call trap() rather than
+ *  directly vectoring the handler.  However, this avoids a lot of code duplication
+ *  and possible bugs.
  */
 void
 trap(Ureg *ur)


@@ 239,13 241,6 @@ trap(Ureg *ur)
 	if(user)
 		up->dbgreg = ur;
 
-ur->cs &= 0xffff;
-ur->ds &= 0xffff;
-ur->es &= 0xffff;
-ur->fs &= 0xffff;
-ur->gs &= 0xffff;
-if(user) ur->ss &= 0xffff;
-
 	/*
 	 *  tell the 8259 that we're done with the
 	 *  highest level interrupt (interrupts are still


@@ 313,20 308,25 @@ lastur = ur;
 void
 dumpregs2(Ureg *ur)
 {
+	ur->cs &= 0xffff;
+	ur->ds &= 0xffff;
+	ur->es &= 0xffff;
+	ur->fs &= 0xffff;
+	ur->gs &= 0xffff;
+
 	if(up)
 		print("registers for %s %d\n", up->text, up->pid);
 	else
 		print("registers for kernel\n");
-	print("FLAGS=%lux TRAP=%lux ECODE=%lux CS=%lux PC=%lux", ur->flags, ur->trap,
+	print("FLAGS=%lux TRAP=%lux ECODE=%lux CS=%4.4lux PC=%lux", ur->flags, ur->trap,
 		ur->ecode, ur->cs, ur->pc);
-	print(" SS=%lux USP=%lux\n", ur->ss, ur->usp);
+	print(" SS=%4.4lux USP=%lux\n", ur->ss&0xffff, ur->usp);
 	print("  AX %8.8lux  BX %8.8lux  CX %8.8lux  DX %8.8lux\n",
 		ur->ax, ur->bx, ur->cx, ur->dx);
 	print("  SI %8.8lux  DI %8.8lux  BP %8.8lux\n",
 		ur->si, ur->di, ur->bp);
 	print("  DS %4.4lux  ES %4.4lux  FS %4.4lux  GS %4.4lux\n",
 		ur->ds, ur->es, ur->fs, ur->gs);
-
 }
 
 void

@@ 168,9 168,9 @@ int
 mount(Chan *new, Chan *old, int flag, char *spec)
 {
 	Pgrp *pg;
-	int order;
-	Mount *nm, *f;
+	int order, flg;
 	Mhead *m, **l;
+	Mount *nm, *f, *um, **h;
 
 	if(CHDIR & (old->qid.path^new->qid.path))
 		error(Emount);


@@ 210,7 210,17 @@ mount(Chan *new, Chan *old, int flag, char *spec)
 	}
 
 	nm = newmount(m, new, flag, spec);
-
+	if(new->mnt != 0) {
+		h = &nm->next;
+		for(um = new->mnt->next; um; um = um->next) {
+			flg = um->flag;
+			if(flg == 0)
+				flg = MAFTER;
+			f = newmount(m, um->to, flg, um->spec);
+			*h = f;
+			h = &f->next;
+		}
+	}
 
 	if(flag & MCREATE)
 		new->flag |= CCREATE;


@@ 221,7 231,9 @@ mount(Chan *new, Chan *old, int flag, char *spec)
 		f->next = nm;
 	}
 	else {
-		nm->next = m->mount;
+		for(f = nm; f->next; f = f->next)
+			;
+		f->next = m->mount;
 		m->mount = nm;
 	}
 

@@ 140,7 140,6 @@ closefgrp(Fgrp *f)
 	}
 }
 
-
 Mount*
 newmount(Mhead *mh, Chan *to, int flag, char *spec)
 {